friend of mine found one dead in her garden today. she rang the RSPCA and her local vet but neither would take the cat's body cos it was dead. she won't touch it, not even with the proverbial bargepole, and she lives in relative isolation so can't rely on any neighbours for help. so she's hoping the foxes will take it tonight.
Most councils will have a department that will remove the corpses of dead animals (pets or wildlife). Tell your friend to give them a call in the morning.
Our old cat died and my H burried her in the garden. Next morning we found her on the lawn where the foxes had dug her up but had not touched the carcas. He reburried her & the same thing happened, In the end we had to put several paving stones on the spot to prevent it happening again.
(this was very distressful for us) So foxes do nothing if they come accross a dead cat.